Functional morphology and anatomy

Question 1

What is true of hearing in fish?

Answer 1

Good in chondrichthyes and actinopterygians

Question 2

What is detection (hearing) based on in fish?

Answer 2

Based on density differences among tissues – Otoliths (in actinopterygians)
– gas bladder

Question 3

What is true of hagfish when maintaining salt/water balance?

Answer 3

Isosmotic

Simple kidneys

Question 4

What is true of lamprey when maintaining salt/water balance?

Answer 4

Similarities with teleosts

Question 5

What is true of Sarcopterygians when maintaining salt/water balance?

Answer 5

Similarities with sharks and rays – convergent evolution?

Question 6

What is true of sharks & rays when maintaining salt/water balance?

Answer 6

• Slightly hyper osmotic to seawater
  – Excrete salt using rectal gland
  – Concentrate urea and TMAO to maintain high osmolarity
  – Excrete dilute urea

Question 7

What is true of marine teleosts when maintaining salt/water balance?

Answer 7

– Hypo-osmotic
– Problem: water loss + salt gain
– Drink water
– Excrete salt (gills and gut)
– Excrete scant urine

Question 8

What is true of freshwater teleost when maintaining salt/water balance?

Answer 8

– Hyperosmotic
– Problem: water gain + salt loss
– Avoid drinking
– Uptake salt (gills)
– Excrete copious urine